Currently, with the development of the electronic communication industry, electronic devices including portable terminals, such as mobile communication terminals (cellular phones), electronic tablets, and personal digital assistants, have become necessary articles of modern life and, therefore, important instruments for transmitting information which changes rapidly.
Generally, such an electronic device includes key buttons and processes signals generated when the key buttons are pressed.
FIG. 1 is a diagram illustrating a configuration of a key button apparatus according to the related art.
Referring to FIG. 1, the key button apparatus 10 includes an opening 121 that is formed in a housing 12 which forms the external appearance of an electronic device, a sealing rubber 13, that has a container shape, is inserted into the opening 121, and seals the opening 121, a key button 11 that is fitted into an accommodating portion 132 of the sealing rubber 13, a shaft portion 111, and a dome switch 14 disposed under the sealing rubber 13. When the key button 11 is pressed downward, the key button 11 through the shaft portion 111 presses a bottom 133 of the sealing rubber 13 and the bottom 133 of the sealing rubber 13 is stretched to press the dome switch 14. When the dome switch 14 is pressed, the connection state thereof is changed and the electronic device recognizes a signal associated with change in the connection state of the dome switch 14.
Since the sealing rubber 13 seals the opening 121 of the housing 12, water is not introduced to the inside of the electronic device. However, in order to prevent the introduction of water using the sealing rubber 13, it is necessary to eliminate gaps between the opening 121 of the housing 12 and the sealing rubber 13. For this purpose, the sealing rubber 13 is formed to be tightly fitted into the opening 121 of the housing 12. In addition, it is necessary to prevent the sealing rubber 13 from being damaged by fatigue caused when the key button 11 is frequently pressed. For this purpose, the sealing rubber 13 is required to have a relatively large thickness. The relatively large thickness of the sealing rubber 13 makes assembling easier to couple the sealing rubber 13 to the opening 121 of the housing 12. However, since the bottom 133 of the sealing rubber 13 that is pressed by the key button 11 is required to have a relatively large thickness operability of the key button 11 is degraded because the bottom 133 is thick.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.